Peter Hannam

The worst of the winter is likely to be over, with the outlook pointing to warmer and drier than normal weather over coming months, conditions that may set up another early fire season.

For Sydney, the last week of July is set to be its warmest for the month, with all days but Sunday forecast to reach 20 degrees or above, setting up yet another heat record for the city.

Most of the country’s south-east can expect mild conditions for the rest of July, said Brett Dutschke, senior meteorologist with Weatherzone. “It looks like all of winter’s strong cold fronts could be confined to July.”

Winter looks likely to be a short one for much of the country. Photo: Coby Keys

While more fronts will move through - with the next due across the south-east at the start of August - the worst of the cold is likely to have passed.

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“[The cold] will come and go before it gets intense,” Mr Dutschke said. “I think it’s the start of the warming trend now.”

A record warm autumn for many regions - including for Sydney - set up a mild start to winter.

Influences from the Indian and Pacific oceans are in a delicate balance.

Meanwhile, conditions in the Pacific remain primed for an El Nino, a weather event that typically leads to warmer and drier conditions across eastern Australia as rainfall patterns shift eastwards.

The latest three-monthly weather forecast released on Thursday indicates the chances remain near the top of the scale that the coming August-October period will be warmer than average for most of the eastern half of the country, particularly for overnight minimums.

Fire risks

Maximum temperatures likely to be on the warm side across eastern Australia. Photo: BoM

Dry conditions are also likely to prevail, particularly for much of Victoria and NSW, which may be bad news for some farmers and add to fire risks.

The northern half and coastal regions of NSW, for instance, have so far received only about 20 per cent of their July average rainfall, said Agata Imielska, senior climatologist for the Bureau of Meteorology.

“The big fire risk areas are those that have had good rains in winter and then dry out when the tap turns off all of a sudden,” Mr Dutschke said.

Minimum temperatures have a high chance of exceeding averages. Photo: BoM

Areas enjoying good rains in recent months include much of South Australia and Victoria, and the central-west and south-west of NSW, he said.

“If those areas dry out quickly, they could be pretty vulnerable come a hotter, windy time.”

Last July was a record warm month for Sydney following a very wet June. Several warm and dry months followed, setting up conditions for a very early start to the fire season in areas such as the Blue Mountains where hundreds of homes were lost in October.

Most of eastern Australia can expect a dry-than-average coming three months. Photo: BoM

“Burn-offs will probably start early this year,” Mr Dutschke said.

'Staggering' warmth

This month is likely to be one of the driest Julys for Sydney in decades, with just 4 millimetres of rain landing in the gauges at Observatory Hill and the prospect of only a few more millimetres at the most before the start of August.

Thursday’s maximum reached 19.8 degrees with forecast tops of 19-23 stretching to next Thursday, about 3-6 degrees above the long-term average for the city.

So far this month, Sydney has had 17 days of at least 18 degrees. On current forecasts, that tally should rise to 24, exceeding the July record of 23 such days set only last year.

“Last July was the warmest on record for Sydney, (and) winter temperatures were reminiscent of spring, not winter,” Ms Imielska said.

“After what was Australia's hottest year on record, it's quite staggering to have yet another spring-like winter,” Ms Imielska said.

“The warm temperatures are a product of clear warm days with little rainfall recorded across Sydney as well as the lack of cold outbreaks resulting in only five days dropping below the July average thus far,” she said.

Melbourne’s averages for this month will be closer to the long-run norm of 13.5 degrees for July but the next seven days should see tops of 15-17 degrees, the bureau said.

“They’ll still notice it, and will take a layer [of clothing] off over the next week or two,” Mr Dutschke said.

The next front, when it comes, is unlikely to “be very long-lived or very cold”, he said. “It won’t take long to warm up again.”

The first half of 2014 was, with 2002, the equal-third warmest half-year worldwide, trailling only 1998 and 2010, NOAA said.

Models run by Australia’s Bureau of Meteorology, NOAA and other agencies continue to tip the likelihood of an El Nino forming later this year.

For now, though, the sea-surface temperatures are warmer than usual in both the western and eastern Pacific. That's one reason why the consistent stalling and reversing of easterly equatorial trade winds - a signal the El Nino is taking hold - has not yet occurred, with above-average warmth in the eastern Indian Ocean perhaps playing a nullifying role.

"It is possible that the effects of the Indian Ocean and Pacific are competing to some degree, and hence are cancelling each other out," the bureau said in its seasonal outlook.

Durng El Ninos, the Pacific typically becomes less of a heat sink, raising the chances that 2014 will beat the current record warm years set in 2005 and 2010 if El Nino-like conditions persist.

The build-up of heat-trapping greenhouse gases from fossil-fuel burning and other human activities is also acting to prime conditions for record warmth, climatologists say.